A New Path to Palsy: Brain Computer Interfaces

The world of Brain-Computer Interfaces (BCIs) is teeming with fascinating developments, ranging from non-invasive solutions like EEG caps to groundbreaking invasive techniques like Elon Musk’s Neuralink. These innovations are leaving an indelible mark on the field of Neurorehabilitation, offering profound hope to individuals who face communication and mobility challenges.

Neuralink’s invasive electrode grid planted inside monkey — playing pong

In the medical field, Brain Computer interfaces are usually present in fields like Amyotrophic lateral sclerosis (ALS) and paralysis; two very difficult conditions that heavily affect one’s ability to move freely.

But let’s take a look at a disability that isn’t explored as much in the BCI field; Cerebral Palsy.

Cerebral palsy, the most common motor disability in children, is a group of neurological disorders that heavily impacts an individual’s ability to move and maintain posture. Palsy is caused by damage or abnormal development in the parts of the brain that control movement. These events can happen before, during, or shortly after birth or in the first few years of life, when the brain is still developing. Examples of these events can include

• Abnormal brain development: Disruptions in the normal growth process of the brain can cause abnormalities that affect the transmission of brain signals. Infections, fever, trauma, or gene mutations can cause the brain to develop abnormally.
• Lack of oxygen in the brain: The brain can become damaged if it does not get enough oxygen for a long time. Very low blood pressure in the mother, a torn uterus, detachment of the placenta, problems with the umbilical cord, or severe trauma to the infant’s head during labor and delivery can prevent oxygen from getting to the brain.
• Infections during pregnancy: Some types of infection that have been linked with cerebral palsy include viruses such as chickenpox, rubella (German measles), cytomegalovirus (CMV), and bacterial infections such as meningitis or encephalitis.
• Brain damage in the first few months or years of life: This can be due to infections, such as meningitis or encephalitis, problems with blood flow to the brain due to stroke, blood clotting problems, abnormal blood vessels, or head injury.
• Genetic abnormalities: Some cases of cerebral palsy may be caused by genetic abnormalities that affect brain development.
• Other factors: Premature birth, low birth weight, multiple births, and exposure to toxins or radiation may also increase the risk of cerebral palsy.

Placenta Detachment — A potential cause of Cerebral Palsy

Now within the realm of cerebral palsy, there are specific types that affect individual’s motor and cognitive function

Let’s take a look at the specific types of Cerebral Palsy

• Damage to the motor cortex: This is the part of the brain that directs muscle movement. Spastic cerebral palsy, which is the most common type of CP, is caused by damage to the motor cortex or pyramidal tracts and is characterized by tight muscles and jerking movements
• Damage to the cerebellum: This is the part of the brain that controls balance and coordination. Ataxic cerebral palsy is caused by damage to the cerebellum and causes problems with balance and coordination
• Damage to the basal ganglia: This is the part of the brain that controls voluntary movements. Dyskinetic cerebral palsy is caused by damage to the basal ganglia and causes problems controlling the movement of the hands, arms, feet, and legs
• Widespread damage to the brain or significant brain malformations: Spastic quadriplegia/quadriparesis is the most severe form of cerebral palsy and is often associated with moderate-to-severe intellectual disability. It is caused by widespread damage to the brain or significant brain malformations

The different types of Plasy and where they affect an individual

It’s important to recognize that there currently is no cure for Cerebral Plasy. But in the status quo, current methods of therapy for individual’s with any sort of Palsy tends to be ineffective. Most common forms include

• Therapy: Physical therapy, occupational therapy, and speech therapy can help improve muscle strength, flexibility, balance, motor development, and mobility. Therapy can also help with everyday activities such as bathing and feeding
• Medication: Medications such as muscle relaxants, anticonvulsants, and botulinum toxin injections can help manage spasticity, seizures, and pain
• Orthotics: Braces, splints, and other orthotic devices can help improve mobility and independence by providing support and correcting posture
• Surgery: In some cases, surgery may be recommended to improve mobility and reduce spasticity. Selective dorsal rhizotomy and multilevel soft tissue surgery are two surgical options that have shown promise in improving ambulatory function in children with cerebral palsy

Common form of physical therapy for Palsy

While these methods are the most common, they still don’t fully bridge a path for individual’s with Palsy to freely communicate, move, or function and you and I do on an everyday basis. While being somewhat ineffective they also are expensive and heavily rely on third person operation. This is where Brain Computer Interfaces can play a role for improving the lives of individual’s with palsy, forever.

Quickly, What are BCI’s? They are interfaces where the brain is able to communicate with an interface (usually a computer) through brain signals. This communication can be done through non invasive electroencephalography (EEG) tools placed on the scalp, or Electromyography (EMG), or invasive electrode grid’s that are placed inside the body to provide more accurate readings of brain and nerve signals.

EEG and EMG’s

With the help of BCI’s can fully revolutionize the way we treat individual’s with Palsy.

One of these ways are Functional Electrical Stimulation or (FES) devices. FES devices use electrical impulses to stimulate paralyzed or weakened muscles. They essentially bypass damaged neural pathways to activate muscles, facilitating improved motor function.

FES System being tested on a child with Palsy

FES technology involves three main technical intricacies:

• Electrode Placement: Electrodes are meticulously positioned on the individual’s skin to ensure precise muscle targeting.
• Stimulation Parameters: Technical parameters such as pulse width, frequency, and amplitude are adjusted to attain the desired level of muscle activation.
• Synchronized Control: FES systems can be synchronized with an individual’s intended movements, such as walking. This ensures that the stimulated muscle contractions align with the desired actions.

When these conditions are employed there is then the step of processing the information

1. Signal Acquisition: Sensors capture brain signals, which are typically electroencephalography (EEG) signals in non-invasive BCIs.

2. Preprocessing: Raw EEG data undergoes preprocessing to remove noise, artifacts, and enhance signal quality.

3. Feature Extraction: Relevant features, often spectral or spatial patterns, are extracted from the preprocessed data.

4. Classification: Machine learning algorithms classify these features into specific brain states or commands.

5. Command Generation: Classified commands are translated into control signals for the FES device.

Translating FES signals process

FES systems have been shown to provide effective therapy to Palsy patient’s in a trial conducted by Australian researchers (https://archivesphysiotherapy.biomedcentral.com/articles/10.1186/s40945-015-0005-x#author-information)

They had basically separated children with Palsy aged 3–10 into two groups. One group would continue normal physical therapy, and the other would use these FES systems. Results were measured at three points: week 0 where the treatment has begun, week 8 where the treatment had stopped, and week 14, six weeks post treatment.

FES therapy used in cycling

While results didn’t show complete physical changes in the group who used FES systems, through a metric they were able to measure the satisfaction rates of the children (and their parents) with Palsy who were being treated. This satisfaction rate was exponentially increased.

While, full physical changes weren’t demonstrated, the FES system was only used for 8 weeks. If these systems were employed for a longer amount of time, there most likely would have been some physically altering result. Regardless, the experiment still showed improvement in the lives of children with Palsy whether that be mental or physical.

Individual with Palsy and parent’s satisfaction rate based on the Canadian Occupational Performance Method (COPM)

In the future, we would need to add effective training protocols to strike a balance between providing enough feedback to facilitate learning without overwhelming the individual. Successful training is the key to harnessing the full potential of BCIs in therapy. With prolonged use of FES therapy in Cerebral Palsy we hope to come across tangible physical results.